It looks like you’re referring to a pontoon storage block (part number 11401-4) manufactured by Keystone Mfg and Supply Co.

About the Product:
– Pontoon Storage Blocks are typically used to support and protect pontoons when storing or transporting boats.
– They help distribute weight evenly and prevent damage to the pontoon tubes.

Possible Details:
– Material: Likely made of durable plastic or rubber.
– Design: May feature grooves or contours to securely hold the pontoon.
– Compatibility: Check if this model fits specific pontoon sizes or brands.

Where to Find It:
– Retailers: Marine supply stores, online marketplaces (e.g., Amazon, eBay, West Marine).
– Manufacturer: Contact Keystone Mfg and Supply Co directly for specifications or replacements.

If you need help locating this part or verifying compatibility, let me know!