A polyurethane elastomer foam having a density of 100 to 500 g/L measured according to DIN 53420 and a Shore A hardness of 40 to 55 measured according to DIN 53505, where the polyurethane elastomer foam is formed by reacting a mixture comprising: 60 to 50 weight percent (wt.%) of a polyol formulation and 40 to 50 wt.% isocyanate pre-polymer, wherein the wt.% is based on the total weight of the mixture; wherein the polyol formulation includes: a glycol mixture consisting of: 85 to 92 wt.% of a polytetramethylene ether glycol (PTMEG) with a weight average molecular weight (MWw) of 1900 to 2100 and a hydroxyl number of 53 to 60; and 4 to 10 wt.% of monoethylene glycol; at least one blowing agent; at least one catalyst; and at least one surfactant, where the wt.% values for the polyol formulation are based on the total weight of the polyol formulation and wherein the at least one blowing agent, the at least one catalyst and the at least one surfactant together bring the wt.% of the polyol formulation to 100 wt.%; and wherein the isocyanate pre-polymer includes: 55 to 70 wt.% of a isocyanate blend having at least 90 wt.% of 4,4'-diphenylmethane diisocyanate; and 30 to 45 wt.% of the PTMEG, wherein the isocyanate pre-polymer has an isocyanate content of 16 to 21 wt.% based on the total weight of the isocyanate pre-polymer, and the polyurethane elastomer foam has a ball rebound of at least 50% measured according to ASTM D3574 on a 10 mm thickness test plate. 60 to 50 weight percent (wt.%) of a polyol formulation and 40 to 50 wt.% isocyanate pre-polymer, wherein the wt.% is based on the total weight of the mixture; wherein the polyol formulation includes: a glycol mixture consisting of: 85 to 92 wt.% of a polytetramethylene ether glycol (PTMEG) with a weight average molecular weight (MWw) of 1900 to 2100 and a hydroxyl number of 53 to 60; and 4 to 10 wt.% of monoethylene glycol; at least one blowing agent; at least one catalyst; and at least one surfactant, where the wt.% values for the polyol formulation are based on the total weight of the polyol formulation and wherein the at least one blowing agent, the at least one catalyst and the at least one surfactant together bring the wt.% of the polyol formulation to 100 wt.%; and a glycol mixture consisting of: 85 to 92 wt.% of a polytetramethylene ether glycol (PTMEG) with a weight average molecular weight (MWw) of 1900 to 2100 and a hydroxyl number of 53 to 60; and 4 to 10 wt.% of monoethylene glycol; 85 to 92 wt.% of a polytetramethylene ether glycol (PTMEG) with a weight average molecular weight (MWw) of 1900 to 2100 and a hydroxyl number of 53 to 60; and 4 to 10 wt.% of monoethylene glycol; at least one blowing agent; at least one catalyst; and at least one surfactant, where the wt.% values for the polyol formulation are based on the total weight of the polyol formulation and wherein the at least one blowing agent, the at least one catalyst and the at least one surfactant together bring the wt.% of the polyol formulation to 100 wt.%; wherein the isocyanate pre-polymer includes: 55 to 70 wt.% of a isocyanate blend having at least 90 wt.% of 4,4'-diphenylmethane diisocyanate; and 30 to 45 wt.% of the PTMEG, wherein the isocyanate pre-polymer has an isocyanate content of 16 to 21 wt.% based on the total weight of the isocyanate pre-polymer, and the polyurethane elastomer foam has a ball rebound of at least 50% measured according to ASTM D3574 on a 10 mm thickness test plate. 55 to 70 wt.% of a isocyanate blend having at least 90 wt.% of 4,4'-diphenylmethane diisocyanate; and 30 to 45 wt.% of the PTMEG, wherein the isocyanate pre-polymer has an isocyanate content of 16 to 21 wt.% based on the total weight of the isocyanate pre-polymer, and the polyurethane elastomer foam has a ball rebound of at least 50% measured according to ASTM D3574 on a 10 mm thickness test plate. <EOS>