The floats of the Kawagoe Festival are what's known as the hoko-dashi type, and they have either three or four wheels.
Literal
Kawagoe [attributive-の] floats [topic-は], so-called hoko-float [quotative-と] called form [copula-で], wheels [subject-が] three [counter-つ], or four [counter-つ] are-attached-[polite-ています].
A cultural-information sentence about the floats of the Kawagoe Hikawa Festival. 山車 (だし) is the general term for a Japanese festival float; 鉾山車 (ほこだし) is a specific subtype with a tall 鉾 (halberd/spear-like decorative pole) on top. いわゆる introduces a technical term the speaker assumes the listener may not know. もしくは is the formal written 'or,' typical of explanatory prose. ~と呼ばれる is the passive 'is called X,' a standard way of introducing names. The mid-sentence ~で is the copula in its te-form linking the 'type' description to the 'wheels' clause.