edward tools drywall corner tool - flexes for perfect 90 degree corner when mudding drywall - high grade stainless steel sheetrock corner trowel - ergonomic grip edward tools edward tools drywall corner tool is the best tool for finishing inside corners of drywall and will cut you corner sanding time in half. the stainless steel one piece designs flexes to create the perfect 90 degree angle and make for the perfect corner. the handle of this corner trowel is an ergonomic rubber design for increased comfort and grip. like all edward tools, this sheetrock corner tool comes comes with a lifetime warranty.