Sold in a set of 2 ($44.50)  or 4 ($88.99) Solid Brass made by 'Faultless' 

For stationary spinet & console pianos with free standing front legs.

Spinet pianos usually range in height from 36" to 40"

• Solid brass wheel 1-1/4” diameter, 11/16” face width
• Caster stem is 5/16” diameter, 1-5/8” stem length
• Brass plated yoke assembly

Supplied with Plastic Sockets -(1/2” diameter) CR-7 - Shown Below

All of our wheels are sold with their own sockets. You will be required to replace the entire wheel / socket assembly to ensure a proper fit. 
You may be required to modify the existing hole in your piano to accommodate the new casters.
Unfortunately there is no reference manual to tell us what wheels would work in each of the over 12,000 pianos manufactured.