Tinksky Cello Endpin Stopper Stop Holder Spike Floor Protector Non-slip Pad (Black) Color: Black with gold-coloured insert. Material: plastic. Total diameter: 9cm. Inner diameter: 2cm. Classic,glossy,dark walnut-effect end pin holder. Protect your floor from scratches and make sure your cello doesn't slip during a practice or performance. The holder is made from solid plastic and has a non-slip rubber foam base which is equally effective on any type of flooring from wood to carpet.